missing data file

parser/parser-lammps/LammpsLogParser.py

@@ -424,7 +424,7 @@ class LammpsMainParser(MainHierarchicalParser):
         self.timestep = []
         self.dump = []
         self.read_data = []
-
+        self.data_file = None
 
     def compile_log_parser(self):
         """Instantiate superContext and construct parser for external data file.